On Thu, 2016-09-29 at 18:57 +0100, Colin King wrote: > Currently U300_DMA_CHANNELS is set to 40, meaning that the shift of 1 can > be more than 32 places, which leads to a 32 bit integer overflow. Fix this > by casting 1 to a u64 (the same type as started_channels) before shifting > it. trivia: > diff --git a/drivers/dma/coh901318.c b/drivers/dma/coh901318.c [] > @@ -1353,7 +1353,7 @@ static ssize_t coh901318_debugfs_read(struct file *file, char __user *buf, > tmp += sprintf(tmp, "DMA -- enabled dma channels\n"); > > for (i = 0; i < U300_DMA_CHANNELS; i++) > - if (started_channels & (1 << i)) > + if (started_channels & ((u64)1 << i)) Using if (started_channels & (1ULL << i)) would be more common. It's also how started_channel bits are set and cleared later in the file. And maybe the for loop should use braces. -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
